1. Field of the Invention
The present invention relates to a referring expression processor for processing referring expressions, a language processor including the referring expression processor and a referring expression processing method.
2. Background Art
Assume that a robot communicates with a person using a speech dialogue system or the like. Assume that there exit a plurality of desks and a plurality of chairs in a room and a person specifies a desk by a referring expression “the white desk with red legs”. Referring expressions are language expressions intended by speakers to pointing at specific entities of interest to hearers. Operation of a language processor of a robot for identifying the desk specified by a person based on the referring expression is referred to as understanding of referring expressions. Operation of the language processor of the robot for generating referring expressions which represent the desk specified by the robot and which is easily understandable by persons in order to make a person identify the desk is referred to as generation of referring expressions. Referring expressions made by persons as a matter of course depend on knowledge of the persons. Accordingly, the language processor has to utilize data on knowledge of persons when carrying out understanding and generation of referring expressions.
A probabilistic model can be used by the language processor to utilize data on knowledge of persons when carrying out understanding and generation of referring expressions.
JP2010-224536A filed by Honda Motor discloses a language processor which handles referring expressions for referring to portions of an object and a probability calculating method used in language processing by the language processor.
However, JP2010-224536A does not disclose a mechanism by which referring expressions including descriptive, anaphoric and deictic expressions are understood and generated in the course of dialogue.
Accordingly, there is a need for a referring expression processor for processing referring expressions, a language processor including the referring expression processor and a referring expression processing method which use a probabilistic model and in which referring expressions including descriptive, anaphoric and deictic expressions are understood and generated in the course of dialogue.